Over the last couple weeks, since our upgrade to Nextcloud 18, users have been reporting their shares disappearing randomly.
After some research, we've found the issue to be a bug in Nextcloud 18. There is an existing bug report in the Nextcloud GitHub repository: Issue #19248. See the official Nextcloud announcement regarding this bug here.
We've manually patched spryCloud with an emergency hot-fix for this issue. Unfortunately, this fix does not bring back the shares that were removed, however it should prevent new shares from disappearing.
Our apologies for any frustration this may have caused you.
Sincerely,
Spry Servers